<?php 
set_time_limit(0);
include_once 'function.php';
function range_download($file) {
 
	$fp = @fopen($file, 'rb');
 
	$size   = filesize($file); // File size
	$length = $size;           // Content length
	$start  = 0;               // Start byte
	$end    = $size - 1;       // End byte
	// Now that we've gotten so far without errors we send the accept range header
	/* At the moment we only support single ranges.
	 * Multiple ranges requires some more work to ensure it works correctly
	 * and comply with the spesifications: http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
	 *
	 * Multirange support annouces itself with:
	 * header('Accept-Ranges: bytes');
	 *
	 * Multirange content must be sent with multipart/byteranges mediatype,
	 * (mediatype = mimetype)
	 * as well as a boundry header to indicate the various chunks of data.
	 */
	header("Accept-Ranges: 0-$length");
	// header('Accept-Ranges: bytes');
	// multipart/byteranges
	// http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
	if (isset($_SERVER['HTTP_RANGE'])) {
		$c_start = $start;
		$c_end   = $end;
		// Extract the range string
		list(, $range) = explode('=', $_SERVER['HTTP_RANGE'], 2);
		// Make sure the client hasn't sent us a multibyte range
		if (strpos($range, ',') !== false) {
			// (?) Shoud this be issued here, or should the first
			// range be used? Or should the header be ignored and
			// we output the whole content?
			header('HTTP/1.1 416 Requested Range Not Satisfiable');
			header("Content-Range: bytes $start-$end/$size");
			// (?) Echo some info to the client?
			exit;
		}
		// If the range starts with an '-' we start from the beginning
		// If not, we forward the file pointer
		// And make sure to get the end byte if spesified
		if ($range[0] == '-') {
			// The n-number of the last bytes is requested
			$c_start = $size - substr($range, 1);
		}
		else {
			$range  = explode('-', $range);
			$c_start = $range[0];
			$c_end   = (isset($range[1]) && is_numeric($range[1])) ? $range[1] : $size;
		}
		/* Check the range and make sure it's treated according to the specs.
		 * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
		 */
		// End bytes can not be larger than $end.
		$c_end = ($c_end > $end) ? $end : $c_end;
		// Validate the requested range and return an error if it's not correct.
		if ($c_start > $c_end || $c_start > $size - 1 || $c_end >= $size) {
			header('HTTP/1.1 416 Requested Range Not Satisfiable');
			header("Content-Range: bytes $start-$end/$size");
			// (?) Echo some info to the client?
			exit;
		}
		$start  = $c_start;
		$end    = $c_end;
		$length = $end - $start + 1; // Calculate new content length
		fseek($fp, $start);
		header('HTTP/1.1 206 Partial Content');
	}
	// Notify the client the byte range we'll be outputting
	header("Content-Range: bytes $start-$end/$size");
	header("Content-Length: $length");
 
	// Start buffered download
	$buffer = 1024 * 4;
	while(!feof($fp) && ($p = ftell($fp)) <= $end) {
		if ($p + $buffer > $end) {
			// In case we're only outputtin a chunk, make sure we don't
			// read past the length
			$buffer = $end - $p + 1;
		}
		set_time_limit(0); // Reset time limit for big files
		echo fread($fp, $buffer);
		flush(); // Free up memory. Otherwise large files will trigger PHP's memory limit.
	}
 
	fclose($fp);
 
}

$error1 = '<!DOCTYPE HTML><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" />'.
		'<meta http-equiv="Refresh" content="5;url=/"/></head>'.
		'<body style="text-align:center;">';
$error2 = '</body></html>';
if (!isset($_SESSION['id']) || empty($_SESSION['id']))
{
	echo $error1.'木有权限观赏视频<br />请<a href="/login.php">登录</a>，如果没有帐号请<a href="/register.php">免费注册</a>'.$error2;
	exit;
}

if (!isset($_GET['id']) || empty($_GET['id']))
{
	echo $error1.'视频不存在'.$error2;
	exit;
}

$id = $_GET['id'];
$conn = conn();
$sql = "SELECT name, free FROM films WHERE id = $id";
$result = mysql_query($sql, $conn);
$row = mysql_fetch_assoc($result);
if (!isset($row['name']))
{
	echo $error1.'视频不存在'.$error2;
	exit;
}
if (0 == $row['free'])
{
	if (!check_permission())
	{
		header('Location:/price.php');
		exit;
	}
}
$film_name = $row['name'];

$fullpath = 'films/'.$film_name;
header("Content-type: video/mp4");
if (isset($_SERVER['HTTP_RANGE']))  { // do it for any device that supports byte-ranges not only iPhone
	range_download($fullpath);
}
else {
	header("Content-Length: ".filesize($fullpath));
	readfile($fullpath);
}
?>